Change that thermostat

By Joel Wensley
Having an old thermostat can cause wild temperature swings, an all-around uncomfortable home and can often cause your furnace to not work at all. This week, I’ll show you how to change that old thermostat so that you can save money by doing it yourself.

First things first, let’s head down to the furnace and shut it off so we won’t have any problems by causing a short circuit. Now we can remove the old thermostat from the wall. Whether you have an old round thermostat or a newer digital type, most have an outer cover and then the base plate that mounts to the wall.

Remove the outer cover and look for the screws, usually just two of them, that mount it to the wall. Make sure and find the screws that do not have wires attached to them. Once you remove the two screws you should be able to remove the thermostat from the wall. Don’t pull it too far away though, it still has the equipment wires attached, that’s the next step.

Now we can remove the equipment wires. If you look closely, you’ll notice the terminals that the wires are connected to have a letter, indicating the function of that wire. As you remove the wire, you may want to mark it with the corresponding letter that you removed it from because you’ll connect it to the new thermostat with the same letter terminals as on the old one. This way, you won’t get it mixed up.

The most common letters that the wires are connected to are R and W for the furnace wires, and if you have air conditioning, those are the G and Y wires.

Now it’s just a matter of playing switcharoo. When connecting the wires to the new thermostat, make sure you get the screws nice and tight so the wire won’t be able to move around beneath the screw. Once the wires are connected you can mount the base plate to the wall and finally place the cover for the thermostat onto the unit.

Now that we’ve completed the installation, I can guarantee the system still won’t work. Remember, we’ve got to turn the furnace back on first. It’s the little things like this that wind up driving you crazy figuring out where you went wrong.

There we go. Done right the first time with very little effort. Always refer to the instruction manual when installing anything new. It can save you a few headaches and can also keep your home healthy and safe.

(Joel Wensley is a licensed mechanical contractor in the state of Michigan, a contributor on Fox 2 News on WJBK-TV Channel 2, and president of Mechanical Heating & Cooling in Dearborn Heights.)